WO2023247900A1

WO2023247900A1 - Hot and cold therapy device with optimised heat removal

Info

Publication number: WO2023247900A1
Application number: PCT/FR2023/050936
Authority: WO
Inventors: Olivier PRORIOL; André BEAUFILS
Original assignee: Bfp Electronique
Priority date: 2022-06-23
Filing date: 2023-06-22
Publication date: 2023-12-28
Also published as: FR3137163A1

Abstract

The invention relates to a device comprising: - a cold applicator (4) thermally connected to a cold surface (10) of a Peltier cell; - a heat applicator (3) having an application axis (3a) which is angularly offset from the application axis of the cold applicator by a value of between 60° and 150°; - a heat sink (14) having a first section touching the hot surface (9) of the Peltier cell and a second section angularly offset relative to the first section that is thermally connected to the heat applicator (10); - an electrical power supply (28) which is configured to be current-adjustable in order to supply the Peltier cell (8) with power; - a microcontroller (33) controlling a regulator (31) for regulating the temperature of the cold applicator (4) and of the heat applicator (3).

Description

Title of the invention: Hot-cold application device, with optimized heat evacuation

Technical area

[OOOlJThe present invention relates to a device designed to apply to a surface in the general sense, heat and cold, generated using a thermoelectric element such as a Peltier cell.

[0002] The object of the invention finds a particularly advantageous application in the field of aesthetic care devices capable of giving a skin surface a sensation of hot or cold, produced using a Peltier cell.

Prior art

[0003] In the state of the art, numerous devices are known using the thermoelectric effect called the Peltier effect which allows, through an electric current, to generate a temperature difference between the two faces of the module or the Peltier cell . For example, US patent 10,512,319 describes an aesthetic care device which gives a skin surface a feeling of warmth or a feeling of freshness so that an effect of accelerating beautification or healing can be got. Such a device includes a plate-shaped Peltier element or cell having a hot surface configured to generate heat and a cold surface configured to absorb heat. These hot and cold surfaces are thermally in contact with respectively hot and cold applicators arranged on the two opposite faces of the device and intended to be in contact with the skin.

[0004] When cold is applied by the cold applicator, it turns out that the temperature of the hot surface of the Peltier element increases significantly so that the effect of applying cold is reduced. Thus, it is necessary to actively release the heat generated in the hot surface. For this purpose, the device comprises a heat sink, part of which is interposed between the hot applicator and the hot surface of the Peltier cell. i The other part of the heat sink is provided with a blowing fan ensuring air circulation between an air inlet and an air outlet arranged on the two opposite sides of the device. By design, such a device does not allow sufficient heat to be evacuated to ensure the application of cold at a predefined low temperature. Even oversizing the heat sink would not allow sufficient heat dissipation.

Presentation of the invention

[0005] The object of the invention aims to remedy the drawbacks of the prior art by proposing a new hot-cold application device, using the thermoelectric effect, and designed to ensure heat evacuation with a view to to reach a cold reference temperature, without oversizing the heat sink.

[0006] To achieve such an objective, the object of the invention relates to a hot-cold application device, comprising in a housing elongated along a longitudinal axis of extension:

- a plate-shaped Peltier cell having a hot surface configured to generate heat and a cold surface configured to absorb heat;

- a cold applicator having an application axis and thermally connected to the cold surface of the Peltier cell;

- a hot applicator having an application axis offset angularly from the application axis of the cold applicator, the hot applicator delimiting a separation space with the hot surface of the Peltier cell;

- an elongated heat sink comprising a contact part housed in at least part of the separation space and having a first section touching the hot surface of the Peltier cell and a second section angularly offset relative to the first section and in connection thermal with hot applicator;

- a temperature sensor configured to measure the temperature of the hot applicator; - a fan configured to produce an air flow to release heat from the heat sink,

- the housing comprising a head end part provided laterally with the hot applicator and the cold applicator whose axes of application are angularly offset from each other in a plane perpendicular to the longitudinal axis according to a value between 60° and 150°, the end head part comprising, in the direction of the longitudinal axis, an air inlet located on one side of the separation space and communicating with at least one air outlet located on the other side of the separation space, the air inlet and the air outlet communicating by an air circuit passing through the heat sink and the device comprising:

- a temperature sensor to measure the temperature of the cold applicator;

- a power supply configured to be adjustable in current to power the Peltier cell;

- a microcontroller controlling a temperature regulator of the cold applicator and the hot applicator, connected to the temperature sensors, the regulator controlling the current supply to the Peltier cell to obtain the application of hot-cold at a given temperature.

[0007] According to an advantageous alternative embodiment, the hot applicator and the cold applicator are mounted in the housing so that the application axes of the hot and cold applicators are angularly offset by a value substantially between 70 ° and 110°.

[0008] According to another characteristic of the invention, the housing comprises a head end portion provided with the hot applicator and the cold applicator mounted laterally so that the axes of application of the hot and cold applicators extend at an elevation angle between 5° and 30°.

[0009] Advantageously, the hot applicator and the cold applicator are each extended by a tubular collar so that the hot applicator and the cold applicator form two prominences extending laterally projecting from the end head portion of the case. Advantageously, the fan is mounted at least in part of the separation space.

[0011] Preferably, a venturi cone is mounted between the air inlet and the fan.

[0012] According to a preferred embodiment feature, the temperature regulator of the cold applicator and the hot applicator is a derived integral proportional regulator.

[0013] Typically, the microcontroller is programmed to control the regulator to ensure the implementation of an operating cycle of the cold applicator or the hot applicator, or of an operating cycle of the hot applicator followed of one operating cycle of the cold applicator.

[0014] According to an example of implementation, the microcontroller controls the operation of the fan and is programmed so that: *during the application of heat by the hot applicator, the regulator adapts the supply current of the Peltier cell to maintain the temperature measured by the temperature sensor of the hot applicator, lower than a hot setpoint temperature,

*before the end of the application of heat by the hot applicator, the fan is started,

*at the end of the application of heat by the hot applicator, the regulator adapts the supply current of the Peltier cell to maintain the temperature measured by the temperature sensor of the cold applicator, higher than a cold setpoint temperature to apply cold using the cold applicator.

Brief description of the drawings

[0015] [Fig. 1] Figure 1 is a general side view of an exemplary embodiment of an application device according to the invention.

[0016][Fig. 2] Figure 2 is a general view of the application device illustrated in Figure 1 but taken from the opposite side.

[0017][Fig. 3] Figure 3 is a top view of the application device according to the invention. [0018] [Fig. 4] Figure 4 is a general view of the interior of the application device according to the invention, without the housing.

[0019] [Fig. 5] Figure 5 is a longitudinal sectional view passing substantially along the cold applicator.

[0020] [Fig. 6] Figure 6 is a perspective view showing in detail the internal architecture of the application device according to the invention.

[0021] [Fig. 7] Figure 7 is a figure similar to Figure 6 but offset substantially by 160° compared to Figure 6.

[0022] [Fig. 8] Figure 8 is a view of a functional block diagram of an exemplary embodiment of an application device according to the invention.

Description of embodiments

[0023] As can be seen from the figures, the object of the invention relates to a device 1 using the thermoelectric effect to generate heat and cold, intended to be applied to a surface such as the skin P of a person . The device 1 comprises a housing 2 of elongated tubular shape extending along a longitudinal axis X. The housing 2 advantageously has a tubular section 2t adapted to form a gripping handle for a person's hand.

[0024] The housing 2 comprises, opposite a proximal part 2a, a head end part 2b provided with a heat application surface 3, designated hot applicator in the remainder of the description and with a surface cold application 4, designated cold applicator in the remainder of the description. As can be seen from the drawings, the hot applicator 3 and the cold applicator 4 are each formed by a smooth plate of a thermally conductive material. The hot applicator 3 and the cold applicator 4 have, in the example illustrated, each an ovoid shape whose tip is oriented opposite the proximal part 2a of the housing.

[0025] By convention, an application axis 3a is defined for the hot applicator 3 and for the cold applicator 4, an application axis 4a. These axes of application 3a, 4a pass substantially through the center of gravity respectively of the surface of the hot applicator 3 and the cold applicator 4, extending substantially perpendicular to this surface. For example, the surface of the hot applicator 3 and the cold applicator 4 is slightly convex or curved. Each axis of application 3a, 4a corresponds to the direction of movement of the device to allow contact of the hot 3 or cold applicator 4 with the skin P of a person.

[0026] According to a characteristic of the invention, the axis of application 3a of the hot applicator 3 is angularly offset from the axis of application 4a of the cold applicator 4 by a value between 60° and 150 °. In other words, in a plane perpendicular to the longitudinal axis cold applicator 4 at an azimuth angle A between 60° and 150° (figure 3). Preferably, the hot applicator 3 and the cold applicator 4 are mounted in the housing so that the application axes 3a, 4a of the hot and cold applicators are angularly offset by an azimuth angle A substantially between 70° and 110°. According to an advantageous alternative embodiment illustrated in the drawings, the axes of application 3a, 4a of the hot and cold applicators are angularly offset by an angle A substantially of the order of 90°.

[0027] As shown in the drawings, the hot applicator 3 and the cold applicator 4 are mounted in the housing, at the end part of the head 2b, substantially at the same level along the longitudinal axis X, being angularly offset according to the circumference of the case as described above. The surfaces of the hot applicator 3 and the cold applicator 4 are oriented to extend laterally from the head end portion 2b of the housing 2. Thus, the axes of application 3a, 4a of the hot applicators 3 and cold 4 intersect the longitudinal axis

It should be noted that in a plane containing the longitudinal axis X, the application axes 3a, 4a of the hot 3 and cold 4 applicators are perpendicular to this longitudinal axis extends substantially parallel to the longitudinal axis elevation P between 5° and 30° and for example of the order of 10°. The angle of elevation P for the hot applicator is taken in the vertical plane passing through the longitudinal axis The cold applicator is taken in the vertical plane passing through the longitudinal axis hot 3 and cold 4 extend at an angle of elevation P, considered in the longitudinal plane passing through the longitudinal axis and cold 4 is directed or open towards the outside, towards the end part of the head 2b so that the axes of application 3a, 4a of the hot 3 and cold applicators 4 present with respect to the tubular section 2t of the housing, an angulation of 90° increased by the angle of elevation p.

[0029] According to another advantageous embodiment, the hot applicator 3 and the cold applicator 4 extend laterally projecting from the head end portion 2b of the housing 2. Thus, the hot applicator 3 and the cold applicator 4 are each extended respectively by a tubular collar 3b, 4b connecting to the tubular part 2t of the housing 2. Thus, the housing 2 has at its end head part 2b, two prominences 3c, 4c projecting relative to to the tubular part 2t, oriented substantially at 90° from each other, one ending 3c with the hot applicator 3 and the other 4c with the cold applicator 4. Thus, the device 1 has a first prominence called hot head 3c and a second prominence called cold head 4c. The preferred angular offset A of around 90° between the cold applicator and the hot applicator facilitates contact operations on the same surface of the skin by a simple pivoting movement of the hand.

To produce hot and cold, the application device 1 comprises a module or a Peltier cell 8 using the thermoelectric effect. Conventionally, the Peltier cell 8 has a plate shape capable of generating a temperature difference between its two faces, namely a hot surface 9 configured to generate heat and a cold surface 10 configured to absorb heat. For example, the Peltier 8 cell used is a 25x25 Peltier cell, ET-2708-15.

[0031] The cold surface 10 of the Peltier cell 8 is thermally connected to the cold applicator 4. Thus, the cold applicator 4 is connected to the cold surface 10 of the Peltier cell 8 directly or via a block of thermally conductive material 10a.

The hot surface 9 of the Peltier cell 8 which is located opposite the cold surface 10, is positioned at the proximal part of the cold head 4c. To the extent that the cold head 4c is angularly offset by 90° relative to the hot head 3c, the hot surface 9 is located at a distance from the hot applicator 3 and delimits a separation space 12 with the hot applicator 3.

According to another characteristic, the hot surface 9 is intended to be thermally connected to the hot applicator 3 by at least one heat sink 14 ensuring heat evacuation. In the example illustrated, the heat sink 14 is in the form of an elongated block made of a thermally conductive material comprising, from one end, a contact part 14a housed in at least part of the space of separation 12. This contact part 14a has a first section touching the hot surface 9 of the Peltier cell 8 and a second section offset angularly with respect to the first section and in thermal connection with the hot applicator 3. The first section of this contact part 14a is angularly offset from the second section at an angle corresponding to the angle A of offset between the axes of application 3a, 4a of the hot 3 and cold applicators 4.

The heat sink 14 is in contact with the hot surface 9 and with the hot applicator 3, directly or indirectly. In the example illustrated, the heat sink 14 is in contact with the hot applicator 3 via a massive support 15 made of a thermally conductive material, and with the hot surface 9 of the Peltier cell, via the intermediate of a support piece 16 made of a thermally conductive material. For example, the solid support 15 and the support part 16 are offset from each other by 90°, forming a single part fixed to the housing. The heat sink 14 is arranged to conventionally have heat evacuation fins. As will be better understood in the remainder of the description, the fins are arranged so as to create an air circuit passing through the heat sink 14 between an air inlet 18 and an air outlet 19 located on either side. other of the separation space 12. The circulation of air through the separation space 12 located between the hot surface 9 and the hot applicator 3 ensures optimized heat evacuation. Thus, the fins are arranged substantially parallel to the longitudinal axis

[0036] According to one characteristic of the invention, the device 1 comprises a fan 21 mounted at least in part of the separation space 12. Thus, the fan 21 is mounted inside the housing 2 between the end of the heat sink 14 delimiting the contact part 14a and the top of the head end part 2b of the housing.

[0037] As can be seen more precisely from Figure 1, the air inlet 18 is arranged at the top of the head end part 2b of the housing. This air inlet 18 is therefore offset along the longitudinal axis in the housing 2 to open at the level of the heat sink 14. Preferably, these two air outlets 19 are arranged diametrically opposite on the housing. These air outlets 19 are offset along the longitudinal axis longitudinal axis The air enters through the air inlet 18 passing through the separation space 12 and the heat sink 14 exiting laterally through the air outlets 19. Heat transfer occurs by convection between the heat sink 14 and the circulating mass of air which serves as a vehicle for the heat.

Advantageously, a venturi cone 23 is arranged between the air inlet 18 and the fan 21 to channel the air entering the fan.

According to another characteristic, the device 1 comprises a temperature sensor 25 configured to measure the temperature of the hot applicator 3 (Figure 8). Likewise, the device 1 includes a temperature sensor 26 configured to measure the temperature of the cold applicator 4. For example, the temperature sensors 25, 26 are installed at the level of the solid support 15 and the support part 16.

[0040] According to another characteristic of the invention, the device 1 comprises a power supply 28 configured to be adjustable in current to power the Peltier cell 8. Advantageously, this power supply 28 comprises an energy source, namely a battery 28a in the example illustrated, connected to a current control circuit 28b supplying the Peltier cell 8. For example, the current control circuit 28b is a BUCK converter.

[0041]This electrical supply 28 is controlled by a regulator 31 controlled by a microcontroller 33. This regulator 31 makes it possible to regulate the temperature of the cold applicator 4 and the hot applicator 3 by controlling the control circuit 28b of the cell Peltier 8, as a function of a set temperature E given by the microcontroller 33. According to an advantageous embodiment, the regulator 31 is a derived integral proportional regulator. This regulator 31 is connected via the microcontroller 33, depending on the thermal cycle applied (hot or cold) either to the measuring sensor 25 of the temperature of the hot applicator 3, or to the measuring sensor 26 of the temperature of the the cold applicator 4.

The microcontroller 33 is adapted to control the operation of the device 1 using, for example, a man-machine interface 34 fixed on the housing 2. The microcontroller 33 is adapted to control the operation, in particular, of the fan 21 and the regulator 31. In particular, the microcontroller 33 is programmed to control the regulator 31 to ensure the implementation of an operating cycle of the cold applicator 4 or an operating cycle of the hot applicator 3, or an operating cycle of the hot applicator 3 followed by an operating cycle of the cold applicator 4. Of course, the microcontroller 33 is programmed to allow adjustment of the duration of each of these operating cycles.

According to an example of implementation, the microcontroller 33 is programmed so that:

*during the application of heat by the hot applicator 3, the regulator 31 adapts the supply current of the Peltier cell 8 to maintain the temperature measured by the temperature sensor 25 of the hot applicator 3, lower than a temperature hot setpoint,

*before the end of the application of heat by the hot applicator 3, the fan 21 is put into operation, for example 30 seconds before the end of the hot cycle,

*at the end of the application of heat by the hot applicator 3, the regulator 31 adapts the supply current of the Peltier cell 8 to maintain the temperature measured by the temperature sensor 26 of the cold applicator 4, greater than a cold set temperature to apply cold through the cold applicator.

[0044] Typically, the microcontroller 33 controls the regulator 31 so that, thanks to the Peltier cell 8, the hot applicator 3 ensures the application of a heat cycle for 5 minutes at a set hot temperature of 44°C followed by a cold cycle applied by the cold applicator 4 for 5 minutes at a cold set temperature of 9°C.

Claims

[Claim 1] Hot-cold application device, comprising in a housing (2) elongated along a longitudinal axis (X) of extension and comprising a head end part:

- a plate-shaped Peltier cell (8) having a hot surface (9) configured to generate heat and a cold surface (10) configured to absorb heat;

- a cold applicator (4) having an application axis (4a) and thermally connected to the cold surface (10) of the Peltier cell;

- a hot applicator (3) having an application axis (3a) angularly offset from the application axis of the cold applicator, the hot applicator (3) delimiting a separation space (12) with the hot surface (9) Peltier cell;

- an elongated heat sink (14) comprising a contact part housed in at least part of the separation space (12) and having a first section touching the hot surface (9) of the Peltier cell and a second section angularly offset relative to the first section and in thermal connection with the hot applicator (3);

- a temperature sensor (25) configured to measure the temperature of the hot applicator (3);

- a fan (21) configured to produce an air flow to release heat from the heat sink (14), characterized in that:

- the housing (2) comprises a head end part provided laterally with the hot applicator (3) and the cold applicator (4) whose axes of application (3a, 4a) are angularly offset from each other in a plane perpendicular to the longitudinal axis (X) according to a value between 60° and 150°, the head end part comprising, in the direction of the longitudinal axis the separation space (12) and communicating with at least one air outlet (19) located on the other side of the separation space (12), the air inlet (18) and the outlet air (19) communicating by an air circuit passing through the heat sink (14) and in that the device includes:

- a temperature sensor (26) for measuring the temperature of the cold applicator (4);

- a power supply (28) configured to be adjustable in current to power the Peltier cell (8);

- a microcontroller (33) controlling a regulator (31) of the temperature of the cold applicator (4) and the hot applicator (3), connected to the temperature sensors (25), (26), the regulator (31 ) controlling the current supply to the Peltier cell to obtain the application of hot-cold at a given temperature.

[Claim 2] Device according to claim 1 according to which the hot applicator (3) and the cold applicator (4) are mounted in the housing (2) so that the application axes (3a), (4a) of the hot and cold applicators are angularly offset by a value substantially between 70° and 110°.

[Claim 3] Device according to the preceding claim according to which the housing (2) comprises a head end portion provided with the hot applicator (3) and the cold applicator (4) mounted laterally so that the axes of application (3a), (4a) hot and cold applicators extend at an elevation angle taken in an elevation plane passing through the longitudinal axis (X) of between 5° and 30°.

[Claim 4] Device according to one of the preceding claims according to which the hot applicator (3) and the cold applicator (4) are each extended by a tubular collar (3b, 4b) so that the hot applicator and the The cold applicator forms two prominences (3c, 4c) extending laterally projecting from the end part of the head of the housing.

[Claim 5] Device according to one of the preceding claims according to which the fan (21) is mounted at least in part of the separation space (12), the air entering the fan (21) from the air inlet (18).

[Claim 6] Device according to one of the preceding claims according to which a venturi cone is mounted between the air inlet (18) and the fan (21).

[Claim 7] Device according to one of the preceding claims according to which the regulator (31) of the temperature of the cold applicator (4) and the hot applicator (3) is a derivative proportional integral regulator.

[Claim 8] Device according to one of the preceding claims according to which the microcontroller (33) is programmed to control the regulator (31) to ensure the implementation of an operating cycle of the cold applicator (4) or of the hot applicator (3), or an operating cycle of the hot applicator (3) followed by an operating cycle of the cold applicator (4).

[Claim 9] Device according to one of the preceding claims according to which the microcontroller (33) controls the operation of the fan (21) and is programmed so that:

*during the application of heat by the hot applicator (9), the regulator (31) adapts the supply current of the Peltier cell (8) to maintain the temperature measured by the temperature sensor (25) of the hot applicator (3), lower than a hot set temperature,

*before the end of the application of heat by the hot applicator, the fan (21) is put into operation,

*at the end of the application of heat by the hot applicator (3), the regulator adapts the supply current of the Peltier cell (8) to maintain the temperature measured by the temperature sensor (26) of the applicator cold (4), higher than a cold set temperature to apply cold by the cold applicator (4).